1. Field of the Invention
The present invention relates to electrical connectors for a flat cable.
2. Description of the Related Art
Japanese patent application Kokai No. 9-35828 discloses an electrical connector of this type.
As FIG. 5 shows, in this connector, a flat cable (flexible board) 51 is inserted into an inserting space of an open mouth in a surface direction of the flat cable, direction A in the figure, so as to be placed on contact sections 54 of terminals which are arranged facing to the open mouth of a housing 52. This inserting space is like a very narrow slit, and slightly larger than the cross-sectional shape of the flat cable 51. To ensure the inserting position of the flat cable 51, restricting blades 55 which contact with upper surface of the inserted flat cable at its lower surfaces are attached at both sides in the cross direction of a flat cable. The restricting blade 55 has a surface edge that is perpendicular to the inserting direction of the flat cable. At the open mouth of the housing 52, a pressure member 56 to open and close the open mouth is attached to the housing, so as to freely rotate. The pressure member 56 enables insertion of a flat cable 51 at open position by opening the inserting space, while it presses the inserted flat cable against the connection section 54 of a terminal.
However, in this type of connector, the entrance of inserting space is so deeply located that it is difficult to see, and is narrow, so that the flat cable 51 can not be inserted in there easily. Moreover, for a connector required to be low profile, it is impossible to design a large inserting.
In addition, in the connector, the position of pressure member 56 is unstable because it is not fixed at the open position, and sometimes it turns over to the closed position unintentionally at the time of inserting a flat cable. In this case, the pressuring member 56 makes it further difficult to see the entrance of the inserting space.
Also, if the front edge of a flat cable hits the surface edge 55A of restricting blade 55 which is supposed to define the inserting position of a flat cable 51, and then an inserting force is applied despite of that, the surface of the flat cable is bent backward so that the cable can not be inserted. The pressure member and restricting blade, like this, worsen above-mentioned problem.
In view of those problems, it is an object of this invention to provide an electrical connector for a flat cable that enables easier insertion of a flat cable.
An electrical connector for a flat cable according to the present invention has a plurality of terminals which are arranged and held in a housing and have contact sections at the position facing to an open mouth of the housing, and a pressure member which can freely turn around a rotational axis positioned in opposite side of flat cable to contact section, wherein the pressure member can freely turn over between an open position which opens inserting space to enable insertion of a flat cable into the open mouth and a closed position which pushes the flat cable towards contact section closing the inserting space.
According to one aspect of the invention, there is provided an electrical connector which comprises a terminal which has bearing section for rotational movement of a pressure member at the rotational axis; and engaging section to hold the pressure member at the open position by engaging force generated by concerted movement between the terminal or the housing and the pressure member when the pressure member turns over to the open position.
The pressure member of this connector with this structure is maintained at open position by its engaging force with terminal or housing, if the pressure member is turned over to open position at the time of inserting a flat cable. Accordingly, inserting space is certainly held open, so that flat cable can be easily inserted.
According to the present invention, an engaging section can be designed to be formed at a terminal or a housing and a pressure member by parallel or perpendicular surface to rotational axis. In any case, engagement is performed at supposed position by increase of surface pressure on the surface.
In a case that the engaging section is formed by parallel surface to the rotational axis, pressure member has a slot to which a part of a support arm of a terminal slides when the pressure member turns over to open position, and the support arm has a shoulder which engages with inner wall of the slot when the pressure member reaches the open position, so that it is as if this inner wall and the shoulder form engaging section which is parallel to rotational axis. The shoulder can be like a cam.
According to another aspect of the invention, a pressure member has a shaft along a rotational axis at both sides of arrangement direction of above-mentioned terminal, there is an engaging piece to turn around and support the shaft in proximity of both sides of connector, and the engaging piece and pressure member have engaging section to hold the pressure member at the open position by engaging force generated by concerted movement when the pressure member is turned over to the open position. Preferably, in this aspect, an engaging piece as a separate member is attached to a housing, and forms an engaging section with the pressure member. It is further preferable if the engaging piece as a separate member is metal piece in view of its strength. This metal piece is attached in the proximity of both sides of housing. In this case, engaging section is formed as a protrusion, such as cam, which is formed on upper edge of the metal piece, so that the shaft of the pressure member can be designed to engage by turning over the top of the protrusion.
According to still another aspect of the invention, a housing holds guides, which are positioned at both sides of the housing in the width direction of a flat cable. The lower edge of the guide is provided in a position so as to guide upper surface of a flat cable when it is inserted at regular position, and slanted inward in the width direction towards inserting direction of flat cable and inward towards housing.
In this aspect, since guides are attached to a housing, even if a front edge of a flat cable hits a surface of the guide at the time of inserting the flat cable, the flat cable is still inserted despite of its bend at the front corner edge because the guides are slanted inward. Therefore, after all the flat cable slides into a regular position, that is, inserting space, losing the bend by its elasticity.
The guide can be designed to be bent to form as a metal piece which is almost right angled to the surface of flat cable and attached to both sides of a housing. Here, upper edge of the guide can be slanted or curved toward tip in the direction of lower edge. The guide of this shape can be easily made as a metal piece. Moreover, even if a flat cable slides onto the upper edge of the guide when it is inserted, it is led downward because of the slant of the tip. In this case, it slides into inserting space offsetting its elasticity by pushing the bend section lightly by finger, and the bend is disappeared.